Lasso select not working, but box select is?
Use the Tweak tool
Disclaimer: I'm a right click selecter. I don't know if there is any difference if you joined the left clikers army.
Since 2.80 version, lasso and box select shortcuts by default only works when the Tweak tool is active (see the keymap first column below).

Box and lasso select tool I think are made for early adopters to make sure to have simple select tools like the would find to expect in other software packages (photoshop...)
Back in the days (&lt;2.79) we didn't had &quot;selection tools&quot; and we just used shortcuts. Tweak tool mimic that situation. I made that my default tool.